1. Field of the Invention
The present invention relates to a honeycomb structure and an exhaust gas purifying apparatus.
2. Discussion of the Background
In recent years, particulates (hereinafter, also referred to as “PM”) such as soot and other toxic components contained in exhaust gases discharged from internal combustion engines of vehicles such as buses and trucks, construction machines, or the like have raised serious problems as contaminants harmful to the environment and the human body.
For this reason, various honeycomb structures made of porous ceramics have been proposed as honeycomb filters to purify (convert) the exhaust gases.
Conventionally-known honeycomb structures as above described include a honeycomb structure having a ceramic block including a combination of multiple honeycomb fired bodies in each of which a large number of cells are longitudinally disposed in parallel with one another with a cell wall interposed therebetween.
JP-A 2006-25574 discloses a honeycomb structure that can secure sufficient capture efficiency even when a cell wall is made thin in order to keep low pressure loss of the honeycomb structure.
Specifically, a conventional honeycomb structure disclosed in JP-A 2006-25574 satisfies the equation 11/6−10/3×A≦B provided that the thickness of a cell wall is A (mm) and the surface area of the cell wall per unit volume is B (m2/cm3).
JP-A 60-141667 discloses a ceramic honeycomb structure material useful as a coating material or an impregnating material in order to improve the strength and airtightness of a ceramic honeycomb structure. JP-A 60-141667 specifically discloses a rotary heat storage type ceramic heat exchanger having high heat exchanger effectiveness and low pressure loss.
The contents of JP-A 2006-25574 and JP-A 60-141667 are incorporated herein by reference in their entirety.